U.S. patent number 4,702,371 [Application Number 06/879,012] was granted by the patent office on 1987-10-27 for container for electrical components.
This patent grant is currently assigned to Hitachi, Ltd., Hitachi Tokyo Electronics Co., Ltd.. Invention is credited to Akio Hoshi, Toshiyuki Oura.
United States Patent |
4,702,371 |
Hoshi , et al. |
October 27, 1987 |
Container for electrical components
Abstract
A container for electrical components is formed of an elongated
tube of a plastic material. A top wall of the tube consists of a
lengthwise-extending transparent window, and electrically
conductive portions sandwiching the transparent window. In order to
prevent the electrostatic breakdown of the electrical components,
which occurs when the electrical components contact the transparent
window, the window is made thinner than the electrically conductive
portions of the top wall of the tube so that the plane including
the lower surface of the window and the plane including the lower
surfaces of the conductive portions are spaced at a predetermined
distance.
Inventors: |
Hoshi; Akio (Isesaki,
JP), Oura; Toshiyuki (Ohme, JP) |
Assignee: |
Hitachi, Ltd. (Tokyo,
JP)
Hitachi Tokyo Electronics Co., Ltd. (Tokyo,
JP)
|
Family
ID: |
15490111 |
Appl.
No.: |
06/879,012 |
Filed: |
June 26, 1986 |
Foreign Application Priority Data
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Jul 10, 1985 [JP] |
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60-150129 |
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Current U.S.
Class: |
206/718; 206/776;
361/212; 361/220 |
Current CPC
Class: |
H05K
13/0084 (20130101) |
Current International
Class: |
H05K
13/00 (20060101); H05F 003/02 (); H05F
003/00 () |
Field of
Search: |
;206/328,45.34,334
;361/212,220,215,222,230 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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12363 |
|
Jun 1979 |
|
JP |
|
45280 |
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May 1980 |
|
JP |
|
125599 |
|
Mar 1982 |
|
JP |
|
121898 |
|
Jul 1984 |
|
JP |
|
1593760 |
|
Jul 1981 |
|
GB |
|
Primary Examiner: Moy; Joseph Man-Fu
Attorney, Agent or Firm: Antonelli, Terry & Wands
Claims
What is claimed is:
1. A one-piece extruded container for semi-conductor devices having
a box-like shape resin encapsulation and a plurality of leads
protruding from at least two side surfaces thereof and bending
along a bottom surface of the devices, the container comprising an
elongated tube formed of a plastic material so that a plurality of
semi-conductor devices can be stored therein, said tube comprising
a bottom wall, spaced side walls extending upwardly from said
bottom wall, and a top wall joined to upper ends of said side
walls, said bottom wall and said side walls being formed of an
electrically conductive plastic material of a substantially equal
thickness, said top wall including a longitudinally extending
transparent window of plastic material integrally extruded with
said side walls, an upper surface of said transparent window is
flush with remaining portions of the top wall formed of the
electrically conductive material, and electrically conductive
portions sandwiching said transparent window and having a thickness
substantially equal to the thickness of said bottom wall and said
side walls, the thickness of said transparent window in said top
wall being smaller than the thickness of said electrically
conductive portions thereof so that a plane including a lower
surface of said window and a plane including the lower surfaces of
said conductive portions are spaced at a predetermined
distance.
2. The container for electrical components according to claim 1,
wherein said bottom wall, said side walls, and the electrically
conductive portions of said top wall consist of conductive
polyvinyl chloride, said transparent window in said top wall
consisting of transparent polyvinyl chloride.
3. The container for electrical components according to claim 2,
wherein said conductive polyvinyl chloride contains carbon.
4. The container for electrical components according to claim 1,
wherein the upper surface of said transparent window in said top
wall and that of said electrically conductive portions thereof are
flush with one another.
5. The container for electrical components according to claim 1,
wherein the thickness of said electrically conductive portions of
said top wall is about 0.9 mm, the thickness of said transparent
window therein being about 0.6 mm.
6. A controller according to claim 1, further comprising a pair of
projections extending in a longitudinal direction of the upper and
lower surface thereof.
7. The container for electrical components according to claim 1,
wherein the portions of said transparent window in said top wall
which are in the vicinity of both ends of said tube are provided
with holes into which a stopper for preventing the falling of said
electrical components is inserted.
8. A one-piece extruded container for storing electrical components
each of which includes a resin-sealed body, a radiation member
extending from said body, and a plurality of leads extending from
said body in a direction opposite to the direction in which said
radiating member extends, the container comprising an elongated
tube of a plastic material, incuding a first housing portion for
accommodating the resin-sealed body of said electrical component, a
second housing portion for accommodating the radiating member of
said electrical component, and a third housing portion for
accommodating the leads of said electrical component, a bottom wall
of said first housing portion, and said second and third housing
portions including an electrically conductive plastic material, an
integrally extruded top wall of said first housing portion
including a transparent window of a plastic material positioned in
the substantially central section thereof and extending in a
longitudinal direction thereof, an upper surface of a top wall of
said housing portion being flush with a top surface of said
transparent window, and electrically conductive portions
sandwiching said transparent window, a thickness of said
transparent window in said top wall being smaller than a thickness
of said electrically conductive portions thereof so that a plane
including a lower surface of said transparent window and a plane
including lower surfaces of said conductive portions are spaced at
a predetermined distance.
9. The container according to claim 8, wherein a bottom wall of
said first housing portion, electrically conductive sections of
said top wall, and said second and third housing portions are
formed of a conductive polyvinyl chloride, said transparent window
in said top wall being formed of transparent polyvinyl
chloride.
10. The container according to claim 9, wherein said conductive
polyvinyl chloride contains carbon.
11. The container according to claim 8, wherein the upper surfaces
of said window in and said electrically conductive portions of said
top wall of said first housing portion are flush with one
another.
12. The container according to claim 8, wherein the thickness of
said electrically conductive portions of said top wall of said
first housing portion is about 0.9 mm, the thickness of said
transparent window therein being about 0.6 mm.
13. The container according to claim 8, wherein said electrical
components stored in said tube are semiconductor devices.
14. The container according to claim 8, wherein the portions of
said transparent window in said first housing portion which are in
the vicinity of both ends of said tube are provided with holes into
which a stopper for preventing the falling of said electrical
components is inserted.
Description
BACKGROUND OF THE INVENTION
This invention relates to a tubular container for storing a
plurality of miniaturized electrical components, and, more
particularly, to a container effectively utilized for storing, for
example, semiconductor devices which are subject to electrostatic
breakdown, especially, semiconductor integrated circuit devices or
IC devices.
A structure formed tubularly so as to store a plurality of IC
devices and having a window of a transparent plastic at a
predetermined portion of an opaque conductive plastic body has been
proposed as a magazine, i.e. a container for storing a plurality of
IC devices. An example of this construction is proposed in, for
example, U.S. Pat. No. 4,327,832 and U.S. Pat. No. 4,463,851. As
apparent from the specifications of the above mentioned patents,
the body of the structure is formed of an opaque conductive plastic
to prevent the same from being electrically charged, and the IC
devices stored therein from being electrostatically destroyed. The
transparent window is provided so that the mark representing the
product name of the IC devices can be easily identified from the
outside.
However a disadvantage of the proposed IC devices resides in the
fact that the IC devices contact the transparent window, not
subjected to an antistatic treatment, and, consequently, the IC
devices are electrostatically destroyed.
In U.S. Pat. No. 4,327,832 electrically conductive plastic internal
projections or legs are provided integrally with a conductive
plastic body on the portion thereof which is in the vicinity of a
transparent window, so as to prevent the IC devices from contacting
the transparent window. In U.S. Pat. No. 4,463,851 it is proposed
to position a transparent window on the outer surface of the top
wall of a tube, and provides a gap, which is capable of preventing
the IC devices from contacting the transparent window, by utilizing
the thickness of the top wall. These prior art containers have
large overall dimensions and slightly large weights.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel container
having a light weight, a high mechanical strength and a simple
construction, and designed so as to mechanically and electrically
protect electrical components.
Another object of the present invention is to provide a novel
container for mechanically and electrically protecting
single-in-line type semiconductor integrated circuit devices.
In accordance with the present invention, the container for storing
electrical components is formed of an elongated tube, and includes
a top wall of an electrically conductive portion, and a transparent
window, with the transparent window being formed to a thickness
less than that of the electrically conductive portion so as to
prevent the electrical components from contacting the inner surface
of the transparent window.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of a container for
electrical components according to the present invention;
FIG. 2 is a sectional view of the container taken along the line
X--X in FIG. 1;
FIG. 3 is an enlarged fragmentary view of the container of FIG.
2;
FIG. 4 is a sectional view of the container with an electrical
component inclined therein;
FIG. 5 is a longitudinal sectional view illustrating a method of
manufacturing a container according to the present invention;
FIG. 6 is a sectional view of another embodiment of the container
according to the present invention;
FIG. 7 is a perspective view of still another embodiment of the
container according to the present invention;
FIG. 8 is a sectional view of the container taken along the line
Y--Y in FIG. 7;
FIG. 9 is a sectional view of a further embodiment of the container
according to the present invention; and
FIG. 10 is a perspective view of a semiconductor integrated circuit
device to be stored in the container of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein like reference numerals are
used throughout the various views to designate like parts and, more
particularly, to FIGS. 1 and 2, according to these figures, the
container is provided with a body generally designated by the
reference numeral 1 formed integrally by using a plastic material
in which the carbon is mixed as an antistatic agent. The body 1 is
formed to a cross-sectionally inverted-U-shaped elongated tube so
that a plurality of DIP (dual in-line package) type IC devices 12
as object articles, each of which has a plurality of leads 16
arranged in two parallel rows, can be stored therein. The tube
includes a bottom wall 1A the substantially intermediate portion of
which projects upward, side walls 1B, 1C extending diagonally
upward from the bottom wall 1A, and a top wall 1D joined to the
upper ends of the side walls 1B, 1C. The bottom wall 1A, side walls
1B, 1C and parts of the top wall 1D, which the IC device 12
contacts, include an electrically conductive plastic material, such
as carbon-mixed polyvinyl chloride.
In the top wall of the tube 1, a transparent window 2, which
includes a non-conductive transparent plastic, such as transparent
polyvinyl chloride, is formed integrally with the conductive parts
thereof. The window 2 is formed as a narrow strip and provided in a
central portion of the top wall of the tube. Namely, the top wall
1D of the tube includes a transparent longitudinally extending
window 2 positioned in the substantially central portion thereof,
and electrically conductive portions 1d sandwiching the transparent
window 2. The tube 1 is provided at both end portions thereof with
bores 13, 13b, 13c, into which stopper pins 15 are inserted after
IC devices 12 have been placed therein, so as to prevent the IC
devices 12 from coming off. As shown in FIG. 2, the upper surfaces
of the conductive portions 1d of the tube 1 and that of the
transparent window 2 are flush with one another, and the thickness
of the window 2 is smaller than that of the conductive portions 1d.
Accordingly, the lower surface 2a of the transparent window 2 is
higher than those 1a of the conductive portions 1d.
Referring to FIG. 3, the top wall 1C has a flat upper surface.
Namely, the upper surface 1b of a conductive portion 1d and that 2b
of the transparent window 2 are flush with each other. The
thickness t.sub.1 of the conductive portion 1d is about 0.9 mm
which is substantially equal to the thickness of the bottom wall 1A
and side walls 1B, 1C. The thickness of the window 2 is about 0.6
mm. Accordingly, a distance d of about 0.3 mm is obtained between
the plane including the lower surface 1a of the conductive portion
1d and that 2a of the plane including the window 2. Due to this
distance d, an IC device (shown by a one-dot chain line) does not
contact the lower surface 2a of the window 2 even when the IC
device 12 is moved.
The thickness of the electrically conductive portion t.sub.1 of,
and that t.sub.2 of the transparent window 2 in, a container
suitably used for storing IC devices 12 are 1.0-0.7 mm and 0.6-0.4
mm, respectively.
As is clearly understood from a manufacturing method, more fully
described hereinbelow, the transparent window 2 and electrically
conductive portions 1d are formed unitarily of the same material,
i.e. polyvinyl chloride, and the bonding strength of boundary
portions B is very high. The part of the lower surface 1a of a
conductive portion has a radius of curvature R of about 0.3 mm.
It is necessary that a part of an IC device 12 does not contact the
lower surface of the transparent window when the IC device is
inclined. According to the present invention, the container is
designed with consideration given to the dimensions of the IC
device 12, in such a manner that, even when the IC device 12 is
inclined as shown by an arrow A in FIG. 4, it contacts not the
lower surface 2a of the window but the wall portions of the
contaner which have the electrical conductivity.
This container can be molded by a molding apparatus shown in FIG.
5, with an electrically conductive body 1 and a transparent window
2 formed unitarily at once. The molding apparatus 3 shown in FIG. 5
is provided with heating cylinders 4, 4', screws 5, 5', first and
second hoppers 6, 7, a die 8 having a cross-sectional shape of the
interior thereof which corresponds to that of the container, a die
8' for use in determining the final dimensions of the container,
and a cooling element 9. The carbon powder and plastic powder 10
are introduced into the first hopper 6, and plastic powder into the
second hopper 7. The plastic materials, softened in the heating
cylinders 4, 4', are extruded continuously by the dies 8, 8' from
the dies 8, 8' to be removed through the cooling element 9. As a
result, a tube as a container in which a body 1 and a transparent
window 2 are unitarily molded is obtained.
The quantity of the carbon powder introduced into the first hopper
6 is determined so that the resistivity of the electrically
conductive portions of the molded container becomes not more than
1.times.10.sup.6 .OMEGA./.quadrature.. As the plastic powder,
polyvinyl chloride powder is selected. The plastic powder may
consists of polystyrol instead of polyvinyl chloride. Since carbon
is mixed in the electrically conductive body 1, this part assumes a
black color.
As shown in FIG. 1, the DIL type IC device 12 is inserted into and
removed from an end opening of the tube 1. The falling of the IC
device 12 placed in the tube 1 is prevented by inserting the
stopper pins 15 into the bores 13a, 13b, 13c made in both end
portions of the tube.
The greater part of the tube 1 includes an antistatically-treated
carbon-containing resin, i.e., having a conductivity, so that the
electrostatic breakdown of the IC device 12 does not occur even
when the IC device contacts the tube 1. However, the resin forming
the transparent window 2 is transparent, i.e. includes a
non-carbon-containing non-conductive resin, and is apt to be
electrically charged. When the IC device 12 floatingly moves in the
tube to contact the transparent window 2, an electrostatic
breakdown of the IC device 12 would occur.
However, according to the present invention, the IC device 12 is
prevented from contacting the transparent window 2, by the
electrically conductive portions of the tube 1 even if the IC
device 12 is floatingly moved in the tube. Therefore, the
electrostatic breakdown of the IC device 12 can be prevented.
Since the lower surface 2a of the transparent window 2 is higher
than that 1a of the top wall of the tube 1 as shown in FIGS. 3 and
4, the moved IC device 12 necessarily contacts the lower surface of
the top wall of the tube 1 first, and is prevented from contacting
the window 2. Since the greater part of the tube 1 includes a
carbon-containing resin, this part is not electrically charged, so
that the electrostatic breakdown of the IC device 12 does not
occur.
In the top wall of the tube 1, the upper surface of 2b of the
transparent window 2 and upper surface 1b of the electrically
conductive portions 1d are flush with one another. thereby enabling
the container to be advantageously manufactured, and advantageously
used as a container for IC devices 12.
Since the upper surface of the top wall of the tube 1 has no
recesses and projections, the dies 8, 8' for forming the tube can
be obtained at a low cost, and be subjected to little during the
formation of the tube. Accordingly, the frequency in replacing the
dies is low, so that the container can be manufactured at a low
cost.
When a plurality of such containers (tubes) are transferred in a
piled state, the upper containers can be stably maintained since
the lower surfaces of the upper containers placed on the upper
surfaces of the lower containers contact the same upper surfaces
reliably without being inclined even if the mentioned lower
surfaces are shifted slightly in the lateral direction.
The embodiment of FIG. 6 is formed of an electrically conductive
tube body 1 and a transparent window 2 in the manner similar to
that in which the above described embodiment is formed and the
materials used to manufacture the second embodiment are the same as
those described hereinabove. The embodiment of FIG. 6 differs from
the first described embodiment in that the parts of side walls of a
tube 1, i.e. inclined wall portions 14 are formed so as to extend
at a predetermined angle toward the positions close to the upper
edge portions of an IC device 12 placed in the tube. Namely, the
angle of the inclined wall portions 14 is determined so that the
width W.sub.T of the inner surface of a top wall 1D of the tube 1
becomes smaller than that W.sub.P of a sealed body of the IC device
12.
Accordingly, in the embodiment of FIG. 6, the floatingly moved IC
device 12 necessarily contacts the inner surface 14a of an inclined
wall portion 14 first, so that the IC device 12 can be prevented
more reliably from contacting the transparent window 2.
FIG. 7 provides an example of a container for storing a SIL
(single-in-line package) type IC device 12. More particularly, in
FIG. 7, an IC device 12 to be inserted in a container includes a
resin-sealed body 12a, a radiating member 17 extending from a side
portion of the body 12a, and a plurality of leads 16 extending from
the side portion of the body 12a which is on the opposite side of
the side portion from which the radiating member 17 extends.
The container accommodating the IC device 12 is formed as an
elongated tube 1 formed of polyvinyl chloride. The tube 1 includes
a first housing portion 100 in which the resin-sealed body 12a of
the IC device is held, a second housing portion 101 in which the
radiating member 17 of the IC device is held, and a third housing
portion in which the leads 16 of the IC device 12 are held. A
bottom wall 100A of the first housing portion, and the second and
third housing portions 101, 102 includes an electrically conductive
plastic material, i.e. carbon-containing polyvinyl chloride. A top
wall 100B of the first housing portion 100 is provided at the
substantially central portion thereof with a transparent window 2,
which includes a non-conductive transparent plastic, such as
transparent polyvinyl chloride, in such a manner that a mark on the
upper surface of the resin-sealed body 12a of the IC device 12 can
be ascertained. The tube has electrically conductive portions 100b
extending so as to sandwich the transparent window 2. The portions
of the transparent window 2 and bottom wall 100A which are in an
end portion of the tube 1 are provided with bores 13a, 13b,
respectively, into which a stopper pin 15 is inserted after the IC
device 12 has been inserted in the tube 1, so as to prevent the IC
device 12 from being dislodged. In order to limit the latteral
movement of the IC device 12 in the first housing portion 100, the
bottom wall 100A and top wall 100B are provided with projections
100a, 100c, respectively.
As shown in FIG. 8, the upper surface of the top wall of the first
housing portion 100 and that of the transparent window 2 are flush
with each other, and the thickness of the transparent window 2 is
smaller than that of the electrically conductive portions 100b.
Accordingly, the lower surface 2a of the transparent window 2 is
higher than those of the electrically conductive portions 100b.
Namely, the construction of the parts of the transparent window 2
and electrically conductive portions 100b which are in the vicinity
of the joint sections thereof is the same as that of the
corresponding parts of the container shown in FIG. 3. The thickness
of the carbon-mixed conductive portions (opaque portions) of the
tube 1 in the embodiment of FIG. 7 is about 0.9 mm, with the
conductive portions being formed to a constant thickness. The
thickness of the transparent window is about 0.6 mm. Therefore,
there is a distance of 0.3 mm between the plane including the lower
surface of the transparent window 2 in and the plane including the
electrically conductive portions 100b.
The container of the embodiment of FIG. 7 is made by using the
molding apparatus 3 shown in FIG. 5, in the same manner as that
described in hereinabove in connection with the embodiment of FIGS.
1-3. Accordingly, the opaque electrically conductive portions of
the tube 1 and the transparent window therein are unitarily formed,
so that these unitarily formed parts do not separate. As is clear
from FIGS. 7 and 8, the container in has a cross-sectionally
H-shaped construction. Namely, the thickness of the second and
third housing portions, between which the first housing portion 100
is sandwiched, is larger than that of the first housing portion 100
so as to prevent the head portion and lower end portion of the
stopper pin 15, which is inserted into the bores 13a, 13b, from
projecting from the upper and lower main surfaces of the second and
third portions 101, 102. This enables a plurality of containers to
be piled up stably without being inclined. Since this container has
a cross-sectionally H-shaped construction, it has a high mechanical
strength.
A PLCC (plastic leaded chip carrier) type IC device has an external
appearance shown in FIG. 10, and includes a resin-sealed body 12a,
and a plurality of leads 16 molded in the shape of the letter "J"
and extending outward from four side surfaces of the body 12a. A
container for storing the IC device 12 is molded to an elongated
tubular shape, which has a cross-sectional shape shown in FIG. 9.
Namely, a tube 1 includes a bottom wall 1A, side walls 1B, 1C
extending upward from the bottom wall 1A, and a top wall 1D joined
to the upper ends of the side walls 1B, 1C. The bottom wall 1A,
side walls 1B, 1C and parts of the top wall 1D, which the IC device
shown in FIG. 10 contacts, includes an electrically conductive
plastic material, such as carbon-mixed polyvinyl chloride. The top
wall 1D of the tube includes a transparent window 2 positioned in
the substantially central section thereof and composed of a
non-conductive transparent plastic, such as transparent polyvinyl
choride, and electrically conductive portions 1d. The upper surface
of the top wall of and that of the transparent window 2 in the tube
1 are flush with each other, and the thickness of the window 2 is
larger than that of the electrically conductive portions 1d of the
tube 1. Accordingly, the lower surface 2a of the transparent window
2 is higher than those of the electrically conductive portions 1d.
Namely, the portions of the tube 1 which are in the vicinity of the
joint sections between the transparent window 2 and conductive
portions 1d are constructed in the same manner as the corresponding
portions of the tube of the embodiment of FIG. 10. The thickness of
the carbon-mixed electrically conductive portions (opaque portions)
of the tube 1 of Embodiment 4 is about 0.8 mm, and the thickness of
the transparent window about 0.55 mm. Accordingly, there is a
distance of about 0.25 mm between the plane including the lower
surface of the window 2 in the top wall 1D and that including the
lower surfaces of the conductive portions 1d thereof. Owe to this
distance, the IC device 12 can be prevented from contacting the
lower surface 2a of the transparent window 2 even if the IC device
12 is moved.
The bottom wall 1A is provided with a pair of projections P.sub.1,
P.sub.2, and the top wall 1D a pair of projections P.sub.3,
P.sub.4, as well. The distance between the projections P.sub.1,
P.sub.2 is larger than that between the projections P.sub.3,
P.sub.4. The reasons way the distances between these projections
are set in this manner is that it is necessary to prevent the
containers of the same construction, when they are stacked, from
sliding sideways and collapsing.
The container of embodiment of FIG. 10 is formed by using the
molding apparatus 3 shown in FIG. 5, in the same manner as the
container described in the embodiment of FIGS. 1-3. Accordingly,
the opaque conductive portions of and the transparent window in the
window in the tube 1 are formed unitarily, so that these parts of
the tube 1 do not separate.
The containers in the above described embodiments have the
following effects.
Since the container body is formed so that a part thereof contacts
the electrical components, such as IC devices 12 stored therein,
the electrical components can be prevented from contacting the
transparent window 2. This can prevent troubles, such as the
electrostatic breakdown of the electrical components, which occurs
if the electrical components contact the window 2 which is easily
electrically charged.
Moreover, since the container body is molded tubularly with the
conductive portions and transparent window 2 formed unitarily, the
rigidity of the container body with respect to the twisting force
and bending force increases thereby preventing the deformation of
the container body.
Furthermore, since the container is molded out of a resin
containing an antistatic agent (metal powder), such as carbon, it
is not electrically charged.
Additionally, since the transparent window is provided, the
interior of the container can be observed thereby enabling the
marks on and the quantity of the electrical components stored in
the container to be readily ascertained.
Moreover, the present invention has the following advantageous
effects over a container such as disclosed in the above referenced
U.S. Pat. No. 4,327,832.
According to the present invention, the tube is not provided on its
inner surface with the special projections such as proposed in U.S.
Pat. No. 4,327,832, and which are formed so as to present the
electrical components from contacting the transparent window.
Therefore, since the construction of the container according to the
present invention is not complicated, the container can be formed
to small dimensions and weight and at a low cost. This is a very
important matter for the container as a transportation container
after its basic problem of mechanically and electrically protecting
electrical components. In the container disclosed in the
above-noted United States patent it is considered possible that the
projections wear or chip off due to the movements of the electrical
components. Moreover, due to the provision of the projections on
the inner surface of the tube and the necessity of leaving a
spacial margin for the electrical components to be placed in the
tube, the volume of the interior of the tube increases. This
necessarily causes an increase in the dimensions of the container
discosed in U.S. Pat. No. 4,327,832.
According to the present invention, the tube is formed so that the
upper surfaces of the electrically conductive portions of the top
wall and that of the transparent wall therein are flush with each
other. Therefore, dust is not deposited on the transparent window,
so that the electrical components stored in the tube can be
observed very easily. According to the container disclosed in U.S.
Pat. No. 4,327,832, there is a difference between the height of the
upper surfaces of the electrically conductive portions of the top
wall of the tube and that of the upper surface of the transparent
window therein. This causes the deposition of dust to occur on the
portions of the upper surface of the transparent window which are
in the vicinity of the stepped portions, and the observation of the
electrical components stored in the tube to be hampered. Moreover,
it is considered possible that these stepped portions chip off.
According to the present invention, the joint sections between the
electrically conductive portions and transparent window extend
substantially flat, and do now have a complicated construction.
This enables the dies in an injection molding machine for the
production of this container to be constructed simply and obtained
at a low cost. Consequently, the container can be manufactured at a
low cost. According to the container disclosed in U.S. Pat. No.
4,327,832, the joint sections between the electrically conductive
portions and transparent window are constructed in the shape of the
letter "V", so that the steps of manufacturing a die for the
production of this container become complicated.
Furthermore, the present invention has advantageous effects over a
container such as proposed aforementioned in U.S. Pat. No.
4,463,851.
According to the present invention, the tube is formed simply with
the thickness of the transparent window in the top wall thereof
reduced. Therefore, the tube has small dimensions and light weight
as previously mentioned. Since the tube is unitarily formed, it is
not deformed, nor does the transparent window separate from the
conductive portions. In the container proposed U.S. Pat. No.
4,463,851, a transparent window is pasted on the whole of the top
wall of the conductive container body provided with a slit thereby
causing the external dimensions and weight of the container to
increase. Due to the pasted construction of the container,
deformation thereof easily occurs. It is considered possible that
the transparent window separate from the tube due to the force
applied to the side walls thereof. Due to the pasted construction
of the tube, it is difficult to mold the conductive body and
transparent window unitarily and simultaneously.
While we have shown and described several embodiments in accordance
with the present invention, it is understood that the same is not
limited thereto but is susceptible to numerous changes and
modifications such as, for example, the shapes and sizes of the
conductive portions and transparent window may be suitably set in
accordance with the those of the electrical components therefore,
we do not intend to be limited to the details shown and described
hereinabove but intend to cover all modifications as encompassed by
the scope of the appended claims.
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